/*-
 * Copyright (c) 2000 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Dieter Baron and Thomas Klausner.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "bsd_getopt_win.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#if !defined(HAVE_GETOPT_LONG)
int    opterr = 1;        /* if error message should be printed */
int    optind = 1;        /* index into parent argv vector */
int    optopt = '?';        /* character checked for validity */
int    optreset;        /* reset getopt */
char    *optarg;        /* argument associated with option */

#define IGNORE_FIRST    (*options == '-' || *options == '+')
#define PRINT_ERROR    ((opterr) && ((*options != ':') \
                      || (IGNORE_FIRST && options[1] != ':')))
#define IS_POSIXLY_CORRECT (getenv("POSIXLY_CORRECT") != NULL)
#define PERMUTE         (!IS_POSIXLY_CORRECT && !IGNORE_FIRST)
/* XXX: GNU ignores PC if *options == '-' */
#define IN_ORDER        (!IS_POSIXLY_CORRECT && *options == '-')

/* return values */
#define    BADCH    (int)'?'
#define    BADARG        ((IGNORE_FIRST && options[1] == ':') \
             || (*options == ':') ? (int)':' : (int)'?')
#define INORDER (int)1

#define    EMSG    ""

#ifdef __cplusplus
extern "C" {
#endif

static int getopt_internal(int, char * const *, const char *);
static int gcd(int, int);
static void permute_args(int, int, int, char * const *);

static char *place = EMSG; /* option letter processing */

/* XXX: set optreset to 1 rather than these two */
static int nonopt_start = -1; /* first non option argument (for permute) */
static int nonopt_end = -1;   /* first option after non options (for permute) */

/* Error messages */
static const char recargchar[] = "option requires an argument -- %c";
static const char recargstring[] = "option requires an argument -- %s";
static const char ambig[] = "ambiguous option -- %.*s";
static const char noarg[] = "option doesn't take an argument -- %.*s";
static const char illoptchar[] = "unknown option -- %c";
static const char illoptstring[] = "unknown option -- %s";


/*
 * Compute the greatest common divisor of a and b.
 */
static int
gcd(int a, int b)
{
    int c;

    c = a % b;
    while (c != 0) {
        a = b;
        b = c;
        c = a % b;
    }
       
    return b;
}

/*
 * Exchange the block from nonopt_start to nonopt_end with the block
 * from nonopt_end to opt_end (keeping the same order of arguments
 * in each block).
 */
static void
permute_args(int panonopt_start,
         int panonopt_end,
         int opt_end,
         char * const *nargv)
{
    int cstart, cyclelen, i, j, ncycle, nnonopts, nopts, pos;
    char *swap;

    /*
     * compute lengths of blocks and number and size of cycles
     */
    nnonopts = panonopt_end - panonopt_start;
    nopts = opt_end - panonopt_end;
    ncycle = gcd(nnonopts, nopts);
    cyclelen = (opt_end - panonopt_start) / ncycle;

    for (i = 0; i < ncycle; i++) {
        cstart = panonopt_end+i;
        pos = cstart;
        for (j = 0; j < cyclelen; j++) {
            if (pos >= panonopt_end)
                pos -= nnonopts;
            else
                pos += nopts;
            swap = nargv[pos];
            /* LINTED const cast */
            ((char **) nargv)[pos] = nargv[cstart];
            /* LINTED const cast */
            ((char **)nargv)[cstart] = swap;
        }
    }
}

/*
 * getopt_internal --
 *    Parse argc/argv argument vector.  Called by user level routines.
 *  Returns -2 if -- is found (can be long option or end of options marker).
 */
static int
getopt_internal(int nargc,
        char * const *nargv,
        const char *options)
{
    char *oli;                /* option letter list index */
    int optchar;

    optarg = NULL;

    /*
     * XXX Some programs (like rsyncd) expect to be able to
     * XXX re-initialize optind to 0 and have getopt_long(3)
     * XXX properly function again.  Work around this braindamage.
     */
    if (optind == 0)
        optind = 1;

    if (optreset)
        nonopt_start = nonopt_end = -1;
start:
    if (optreset || !*place) {        /* update scanning pointer */
        optreset = 0;
        if (optind >= nargc) {          /* end of argument vector */
            place = EMSG;
            if (nonopt_end != -1) {
                /* do permutation, if we have to */
                permute_args(nonopt_start, nonopt_end,
                    optind, nargv);
                optind -= nonopt_end - nonopt_start;
            }
            else if (nonopt_start != -1) {
                /*
                 * If we skipped non-options, set optind
                 * to the first of them.
                 */
                optind = nonopt_start;
            }
            nonopt_start = nonopt_end = -1;
            return -1;
        }
        if ((*(place = nargv[optind]) != '-')
            || (place[1] == '\0')) {    /* found non-option */
            place = EMSG;
            if (IN_ORDER) {
                /*
                 * GNU extension: 
                 * return non-option as argument to option 1
                 */
                optarg = nargv[optind++];
                return INORDER;
            }
            if (!PERMUTE) {
                /*
                 * if no permutation wanted, stop parsing
                 * at first non-option
                 */
                return -1;
            }
            /* do permutation */
            if (nonopt_start == -1)
                nonopt_start = optind;
            else if (nonopt_end != -1) {
                permute_args(nonopt_start, nonopt_end,
                    optind, nargv);
                nonopt_start = optind -
                    (nonopt_end - nonopt_start);
                nonopt_end = -1;
            }
            optind++;
            /* process next argument */
            goto start;
        }
        if (nonopt_start != -1 && nonopt_end == -1)
            nonopt_end = optind;
        if (place[1] && *++place == '-') {    /* found "--" */
            place++;
            return -2;
        }
    }
    if ((optchar = (int)*place++) == (int)':' ||
        (oli = strchr(options + (IGNORE_FIRST ? 1 : 0), optchar)) == NULL) {
        /* option letter unknown or ':' */
        if (!*place)
            ++optind;
        if (PRINT_ERROR)
            fprintf(stderr, illoptchar, optchar);
        optopt = optchar;
        return BADCH;
    }
    if (optchar == 'W' && oli[1] == ';') {        /* -W long-option */
        /* XXX: what if no long options provided (called by getopt)? */
        if (*place) 
            return -2;

        if (++optind >= nargc) {    /* no arg */
            place = EMSG;
            if (PRINT_ERROR)
                fprintf(stderr, recargchar, optchar);
            optopt = optchar;
            return BADARG;
        } else                /* white space */
            place = nargv[optind];
        /*
         * Handle -W arg the same as --arg (which causes getopt to
         * stop parsing).
         */
        return -2;
    }
    if (*++oli != ':') {            /* doesn't take argument */
        if (!*place)
            ++optind;
    } else {                /* takes (optional) argument */
        optarg = NULL;
        if (*place)            /* no white space */
            optarg = place;
        /* XXX: disable test for :: if PC? (GNU doesn't) */
        else if (oli[1] != ':') {    /* arg not optional */
            if (++optind >= nargc) {    /* no arg */
                place = EMSG;
                if (PRINT_ERROR)
                    fprintf(stderr, recargchar, optchar);
                optopt = optchar;
                return BADARG;
            } else
                optarg = nargv[optind];
        }
        place = EMSG;
        ++optind;
    }
    /* dump back option letter */
    return optchar;
}

/*
 * getopt --
 *    Parse argc/argv argument vector.
 *
 * [eventually this will replace the real getopt]
 */
int
getopt(int nargc, char * const *nargv, const char *options)
{
    int retval;

    if ((retval = getopt_internal(nargc, nargv, options)) == -2) {
        ++optind;
        /*
         * We found an option (--), so if we skipped non-options,
         * we have to permute.
         */
        if (nonopt_end != -1) {
            permute_args(nonopt_start, nonopt_end, optind,
                       nargv);
            optind -= nonopt_end - nonopt_start;
        }
        nonopt_start = nonopt_end = -1;
        retval = -1;
    }
    return retval;
}

/*
 * getopt_long --
 *    Parse argc/argv argument vector.
 */
int
getopt_long(int nargc,
        char * const *nargv,
        const char *options,
        const struct option *long_options,
        int *idx)
{
    int retval;

    /* idx may be NULL */

    if ((retval = getopt_internal(nargc, nargv, options)) == -2) {
        char *current_argv, *has_equal;
        size_t current_argv_len;
        int i, match;

        current_argv = place;
        match = -1;

        optind++;
        place = EMSG;

        if (*current_argv == '\0') {        /* found "--" */
            /*
             * We found an option (--), so if we skipped
             * non-options, we have to permute.
             */
            if (nonopt_end != -1) {
                permute_args(nonopt_start, nonopt_end,
                    optind, nargv);
                optind -= nonopt_end - nonopt_start;
            }
            nonopt_start = nonopt_end = -1;
            return -1;
        }
        if ((has_equal = strchr(current_argv, '=')) != NULL) {
            /* argument found (--option=arg) */
            current_argv_len = has_equal - current_argv;
            has_equal++;
        } else
            current_argv_len = strlen(current_argv);
        
        for (i = 0; long_options[i].name; i++) {
            /* find matching long option */
            if (strncmp(current_argv, long_options[i].name,
                current_argv_len))
                continue;

            if (strlen(long_options[i].name) ==
                (unsigned)current_argv_len) {
                /* exact match */
                match = i;
                break;
            }
            if (match == -1)        /* partial match */
                match = i;
            else {
                /* ambiguous abbreviation */
                if (PRINT_ERROR)
                    fprintf(stderr, ambig, (int)current_argv_len,
                         current_argv);
                optopt = 0;
                return BADCH;
            }
        }
        if (match != -1) {            /* option found */
                if (long_options[match].has_arg == no_argument
                && has_equal) {
                if (PRINT_ERROR)
                    fprintf(stderr, noarg, (int)current_argv_len,
                         current_argv);
                /*
                 * XXX: GNU sets optopt to val regardless of
                 * flag
                 */
                if (long_options[match].flag == NULL)
                    optopt = long_options[match].val;
                else
                    optopt = 0;
                return BADARG;
            }
            if (long_options[match].has_arg == required_argument ||
                long_options[match].has_arg == optional_argument) {
                if (has_equal)
                    optarg = has_equal;
                else if (long_options[match].has_arg ==
                    required_argument) {
                    /*
                     * optional argument doesn't use
                     * next nargv
                     */
                    optarg = nargv[optind++];
                }
            }
            if ((long_options[match].has_arg == required_argument)
                && (optarg == NULL)) {
                /*
                 * Missing argument; leading ':'
                 * indicates no error should be generated
                 */
                if (PRINT_ERROR)
                    fprintf(stderr, recargstring, current_argv);
                /*
                 * XXX: GNU sets optopt to val regardless
                 * of flag
                 */
                if (long_options[match].flag == NULL)
                    optopt = long_options[match].val;
                else
                    optopt = 0;
                --optind;
                return BADARG;
            }
        } else {            /* unknown option */
            if (PRINT_ERROR)
                fprintf(stderr, illoptstring, current_argv);
            optopt = 0;
            return BADCH;
        }
        if (long_options[match].flag) {
            *long_options[match].flag = long_options[match].val;
            retval = 0;
        } else 
            retval = long_options[match].val;
        if (idx)
            *idx = match;
    }
    return retval;
}

#ifdef __cplusplus
}
#endif
#endif /* !GETOPT_LONG || !GETOPT */
